The invention relates to a hydrodynamic retarder comprising—a rotor (1) and a stator (2) which form a working chamber (3) with each other;—a first working medium connection (6);—a second working medium connection (7); and—a working medium container (4) that has an outlet (10), which is connected to the first working medium connection via a line, and an inlet (11), which is connected to the second working medium connection via a line; wherein—the working medium container is made of two housing parts (8, 9), which are joined together along a parting line (12). According to the invention:—the two housing parts together enclose the working medium storage volume;—one of the two housing parts simultaneously forms a part of a retarder housing (14) which supports or forms the stator and partly forms all or some of the working medium-conducting connections between the working medium storage volume and the working chamber; and—a separating plate (13) is inserted between, the two housing parts, said separating plate together with one or both of the housing parts forming cavities for the working medium-conducting connections and/or the working medium storage volume.